Materials

Throughout the battery from a single cell to a complete pack there are many different materials. Hence it is important to look at those in terms of their characteristics and application in battery design.

This page will be arranged A to Z so that you can quickly scan down and find the appropriate section.

Aerogel – synthetic porous ultralight foam material derived from a gel, in which the liquid component for the gel has been replaced with a gas. Possible uses in battery packs based on it’s thermal insulation properties.

Aluminium

Used in electrical busbars, cell cases, module housings and for pack cases. Hence a number of different grades of aluminium based on the requirements from electrical resistance, thermal conductivity, strength and corrosion resistance.

Cobalt – used in the active materials for battery cathodes. A huge amount of work to reduce and remove this element based on cost and serious ethical sourcing and refining issues.

Copper

HV and LV Busbars, electrical tracks, connectors and for some anode current collectors, here ~10µm thick.

Dielectric Coolant – an array of oils and synthetic liquids that are dielectric and hence prevent or quench electric discharge. There are single-phase and two-phase dielectrics that give a number of options for submersing the cells directly into the coolant. We have assembled a list of key dielectric parameters required for battery cooling: What are the key parameters for dielectric fluids as used in a battery pack?

Ethylene Glycol – organic compound used as a coolant, normally mixed 50:50 with water and then flows through isolated coolant plates that the cells interface with.

Graphite

An amorphous form of carbon, made of carbon atoms bound hexagonally in sheets. It is used as a thermal-insulating electrical-conductor, as a nuclear-reactor moderator and as a self-lubricant. In lithium ion batteries it is used as the anode.

Hilumin – an electro nickel-plated diffusion annealed steel strip for battery applications where low contact resistance and high corrosion resistance is required. Trademark of Tata Steel.

Lithium

Lithium is a a soft, silvery-white alkali metal. Atomic number of 3 and symbol Li.

Manganese – used in the active materials for battery cathodes.

Mica

Silicate minerals used in a thin sheet form as a thermal barrier in battery pack designs to contain thermal runaway.

Nickel

Pure nickel is malleable and ductile, and is resistant to corrosion in air or water, and hence is used as a protective coating on busbars or just at busbar joints.

Nickel Plating – process that can enhance the corrosion resistance, durability, hardness, conductivity, and heat-resistance of a component.

Niobium – lots of interest as a substituted element into Nickel rich NMC chemistry to improve stability and hence reduce degradation.

Plastic

A vast array of plastics are used across the battery pack for structure, sealing, isolation and protection.

TIM – Thermal Interface Material

Normally a silicon based compound loaded with graphite to improve it’s thermal conductivity. The purpose of thermal interface materials (TIM) is to transfer heat between two solid surfaces. In the case of a battery this is normally between the outer surface of the cell case and a cooling plate.

V0 Plastics – sometimes used as an abbreviation to describe a plastic that meets the UL94:V-0 certification. The tested material has to self extinguish within 10 seconds on a vertical part allowing for drops of plastic that are not inflamed.